Artificial leaf for harnessing sunlight

Using a
nanocomposite, researchers have made a thin-film device that can absorb
sunlight like a natural leaf and split water, making it potentially useful for
generating hydrogen fuel1.

Producing
hydrogen by harnessing the Sun’s power depends on various factors such as
light-absorbing efficiency, charge separation and migration in a photocatalyst.
It is difficult to make such a versatile catalyst. Most catalysts can absorb
only the ultraviolet rays of sunlight.

Scientists
from the CSIR-National Chemical Laboratory, Pune, prepared a wireless
photochemical cell by using a nanocomposite made of gold nanoparticles,
titanium dioxide and specific quantum dots.

The cell was
dipped in an aqueous solution and exposed to sunlight. A camera recorded showed
instant generation of hydrogen bubbles. The cell exhibited a power conversion
efficiency of 5.6% — much higher than a similar wired cell.

When exposed
to sunlight for 25 hours, the wireless cell retained its efficiency without any
light-induced corrosion. The wireless cell doesn’t need any external voltage and
performs better than existing solar cells.

“In the
future, such cells can be integrated with cars to generate and store hydrogen
fuel,” says lead researcher Chinnakonda S. Gopinath.